Purpose :
There have been few reports about characteristics of optic disc in high myopia. The study aims to describe optic disc tilting, rotation and peripapillary atrophy (PPA) observed in Chinese with high myopia and to investigate factors associated with such appearance.

Methods :
The ZOC-BHVI High Myopia Registry Study examined 901 Chinese aged between 7 and 70 years. The eye examination included disc photography, standardized refraction and axial length (AL) measured with Lenstar. As all subjects included had bilateral high myopia, right eye was chosen from each one for analysis. Using online website (www.eyegrader.com), the tilt ratio, defined by the ratio of the shortest to longest diameter of the optic disc, and the area ratio of PPA to optic disc (D) were measured in disc photographs. Main outcomes were the rate of optic disc titling, rotation and PPA and the associated factors of these three signs. The Mann–Whitney U test was used to compare frequencies. Correlation studies were performed by univariate logistic regression analysis or linear regression analysis as appropriate.

Results :
Mean subject age, spherical equivalent refraction and AL were 22.8±12.4 years (range, 7–70 years), -9.4±3.5 diopters (range, -24.5 to -6 .0 diopters) and 27.5±1.7 mm (range, -23.9 to 34.6 mm), respectively. The rate of optic disc tilting, rotation and PPA were respectively 79.7%, 36.1% and 93.7%. The mean ratio of tilt and PPA/D area were 0.61±0.01 and 1.1 ±0.05. In the 718 subjects with tilted disks, 317 (44.2%) were male and 401(55.8%) were female (P=0.02).The most common rotation direction was inferotemporal (94.8%), followed by superior temporal (2.7%) and inferior (2.5%).In regression analysis, a tilted disk appearance was strongly associated with the occurrence of rotation and PPA(P<0.0001).Tilt ratio was strongly associated with age, AL and PPA/D area ratio (P=0.0031, P=0.0093, P=0.0030, and P<0.0001, respectively). There were no significant parameters associated with the occurrence of optic disc rotation. The occurrence of PPA was significantly associated with age and AL (P=0.0070 and P<0.0001, respectively).

Conclusions :
PPA, disc tilting and rotation are very common in high myopia eyes. The degree of tilt disc was significant positively correlated with age, AL and PPA/D area ratio. A strong positive correlation was observed between the occurrence of PPA and both age and AL.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.